open-nomad/api/allocations.go
Mahmood Ali 2ebbffad12 exec: api: handle closing errors differently
refactor the api handling of `nomad exec`, and ensure that we process
all received events before handling websocket closing.

The exit code should be the last message received, and we ought to
ignore any websocket close error we receive afterwards.

Previously, we used two channels: one for websocket frames and another
for handling errors. This raised the possibility that we processed the
error before processing the frames, resulting into an "unexpected EOF"
error.
2021-05-25 11:19:42 -04:00

484 lines
14 KiB
Go

package api
import (
"context"
"fmt"
"io"
"sort"
"time"
)
var (
// NodeDownErr marks an operation as not able to complete since the node is
// down.
NodeDownErr = fmt.Errorf("node down")
)
const (
AllocDesiredStatusRun = "run" // Allocation should run
AllocDesiredStatusStop = "stop" // Allocation should stop
AllocDesiredStatusEvict = "evict" // Allocation should stop, and was evicted
)
const (
AllocClientStatusPending = "pending"
AllocClientStatusRunning = "running"
AllocClientStatusComplete = "complete"
AllocClientStatusFailed = "failed"
AllocClientStatusLost = "lost"
)
// Allocations is used to query the alloc-related endpoints.
type Allocations struct {
client *Client
}
// Allocations returns a handle on the allocs endpoints.
func (c *Client) Allocations() *Allocations {
return &Allocations{client: c}
}
// List returns a list of all of the allocations.
func (a *Allocations) List(q *QueryOptions) ([]*AllocationListStub, *QueryMeta, error) {
var resp []*AllocationListStub
qm, err := a.client.query("/v1/allocations", &resp, q)
if err != nil {
return nil, nil, err
}
sort.Sort(AllocIndexSort(resp))
return resp, qm, nil
}
func (a *Allocations) PrefixList(prefix string) ([]*AllocationListStub, *QueryMeta, error) {
return a.List(&QueryOptions{Prefix: prefix})
}
// Info is used to retrieve a single allocation.
func (a *Allocations) Info(allocID string, q *QueryOptions) (*Allocation, *QueryMeta, error) {
var resp Allocation
qm, err := a.client.query("/v1/allocation/"+allocID, &resp, q)
if err != nil {
return nil, nil, err
}
return &resp, qm, nil
}
// Exec is used to execute a command inside a running task. The command is to run inside
// the task environment.
//
// The parameters are:
// * ctx: context to set deadlines or timeout
// * allocation: the allocation to execute command inside
// * task: the task's name to execute command in
// * tty: indicates whether to start a pseudo-tty for the command
// * stdin, stdout, stderr: the std io to pass to command.
// If tty is true, then streams need to point to a tty that's alive for the whole process
// * terminalSizeCh: A channel to send new tty terminal sizes
//
// The call blocks until command terminates (or an error occurs), and returns the exit code.
func (a *Allocations) Exec(ctx context.Context,
alloc *Allocation, task string, tty bool, command []string,
stdin io.Reader, stdout, stderr io.Writer,
terminalSizeCh <-chan TerminalSize, q *QueryOptions) (exitCode int, err error) {
s := &execSession{
client: a.client,
alloc: alloc,
task: task,
tty: tty,
command: command,
stdin: stdin,
stdout: stdout,
stderr: stderr,
terminalSizeCh: terminalSizeCh,
q: q,
}
return s.run(ctx)
}
func (a *Allocations) Stats(alloc *Allocation, q *QueryOptions) (*AllocResourceUsage, error) {
var resp AllocResourceUsage
path := fmt.Sprintf("/v1/client/allocation/%s/stats", alloc.ID)
_, err := a.client.query(path, &resp, q)
return &resp, err
}
func (a *Allocations) GC(alloc *Allocation, q *QueryOptions) error {
var resp struct{}
_, err := a.client.query("/v1/client/allocation/"+alloc.ID+"/gc", &resp, nil)
return err
}
func (a *Allocations) Restart(alloc *Allocation, taskName string, q *QueryOptions) error {
req := AllocationRestartRequest{
TaskName: taskName,
}
var resp struct{}
_, err := a.client.putQuery("/v1/client/allocation/"+alloc.ID+"/restart", &req, &resp, q)
return err
}
func (a *Allocations) Stop(alloc *Allocation, q *QueryOptions) (*AllocStopResponse, error) {
var resp AllocStopResponse
_, err := a.client.putQuery("/v1/allocation/"+alloc.ID+"/stop", nil, &resp, q)
return &resp, err
}
// AllocStopResponse is the response to an `AllocStopRequest`
type AllocStopResponse struct {
// EvalID is the id of the follow up evalution for the rescheduled alloc.
EvalID string
WriteMeta
}
func (a *Allocations) Signal(alloc *Allocation, q *QueryOptions, task, signal string) error {
req := AllocSignalRequest{
Signal: signal,
Task: task,
}
var resp GenericResponse
_, err := a.client.putQuery("/v1/client/allocation/"+alloc.ID+"/signal", &req, &resp, q)
return err
}
// Allocation is used for serialization of allocations.
type Allocation struct {
ID string
Namespace string
EvalID string
Name string
NodeID string
NodeName string
JobID string
Job *Job
TaskGroup string
Resources *Resources
TaskResources map[string]*Resources
AllocatedResources *AllocatedResources
Services map[string]string
Metrics *AllocationMetric
DesiredStatus string
DesiredDescription string
DesiredTransition DesiredTransition
ClientStatus string
ClientDescription string
TaskStates map[string]*TaskState
DeploymentID string
DeploymentStatus *AllocDeploymentStatus
FollowupEvalID string
PreviousAllocation string
NextAllocation string
RescheduleTracker *RescheduleTracker
PreemptedAllocations []string
PreemptedByAllocation string
CreateIndex uint64
ModifyIndex uint64
AllocModifyIndex uint64
CreateTime int64
ModifyTime int64
}
// AllocationMetric is used to deserialize allocation metrics.
type AllocationMetric struct {
NodesEvaluated int
NodesFiltered int
NodesAvailable map[string]int
ClassFiltered map[string]int
ConstraintFiltered map[string]int
NodesExhausted int
ClassExhausted map[string]int
DimensionExhausted map[string]int
QuotaExhausted []string
ResourcesExhausted map[string]*Resources
// Deprecated, replaced with ScoreMetaData
Scores map[string]float64
AllocationTime time.Duration
CoalescedFailures int
ScoreMetaData []*NodeScoreMeta
}
// NodeScoreMeta is used to serialize node scoring metadata
// displayed in the CLI during verbose mode
type NodeScoreMeta struct {
NodeID string
Scores map[string]float64
NormScore float64
}
// Stub returns a list stub for the allocation
func (a *Allocation) Stub() *AllocationListStub {
return &AllocationListStub{
ID: a.ID,
EvalID: a.EvalID,
Name: a.Name,
Namespace: a.Namespace,
NodeID: a.NodeID,
NodeName: a.NodeName,
JobID: a.JobID,
JobType: *a.Job.Type,
JobVersion: *a.Job.Version,
TaskGroup: a.TaskGroup,
DesiredStatus: a.DesiredStatus,
DesiredDescription: a.DesiredDescription,
ClientStatus: a.ClientStatus,
ClientDescription: a.ClientDescription,
TaskStates: a.TaskStates,
DeploymentStatus: a.DeploymentStatus,
FollowupEvalID: a.FollowupEvalID,
RescheduleTracker: a.RescheduleTracker,
PreemptedAllocations: a.PreemptedAllocations,
PreemptedByAllocation: a.PreemptedByAllocation,
CreateIndex: a.CreateIndex,
ModifyIndex: a.ModifyIndex,
CreateTime: a.CreateTime,
ModifyTime: a.ModifyTime,
}
}
// ServerTerminalStatus returns true if the desired state of the allocation is
// terminal.
func (a *Allocation) ServerTerminalStatus() bool {
switch a.DesiredStatus {
case AllocDesiredStatusStop, AllocDesiredStatusEvict:
return true
default:
return false
}
}
// ClientTerminalStatus returns true if the client status is terminal and will
// therefore no longer transition.
func (a *Allocation) ClientTerminalStatus() bool {
switch a.ClientStatus {
case AllocClientStatusComplete, AllocClientStatusFailed, AllocClientStatusLost:
return true
default:
return false
}
}
// AllocationListStub is used to return a subset of an allocation
// during list operations.
type AllocationListStub struct {
ID string
EvalID string
Name string
Namespace string
NodeID string
NodeName string
JobID string
JobType string
JobVersion uint64
TaskGroup string
AllocatedResources *AllocatedResources `json:",omitempty"`
DesiredStatus string
DesiredDescription string
ClientStatus string
ClientDescription string
TaskStates map[string]*TaskState
DeploymentStatus *AllocDeploymentStatus
FollowupEvalID string
RescheduleTracker *RescheduleTracker
PreemptedAllocations []string
PreemptedByAllocation string
CreateIndex uint64
ModifyIndex uint64
CreateTime int64
ModifyTime int64
}
// AllocDeploymentStatus captures the status of the allocation as part of the
// deployment. This can include things like if the allocation has been marked as
// healthy.
type AllocDeploymentStatus struct {
Healthy *bool
Timestamp time.Time
Canary bool
ModifyIndex uint64
}
type AllocatedResources struct {
Tasks map[string]*AllocatedTaskResources
Shared AllocatedSharedResources
}
type AllocatedTaskResources struct {
Cpu AllocatedCpuResources
Memory AllocatedMemoryResources
Networks []*NetworkResource
Devices []*AllocatedDeviceResource
}
type AllocatedSharedResources struct {
DiskMB int64
Networks []*NetworkResource
Ports []PortMapping
}
type PortMapping struct {
Label string
Value int
To int
HostIP string
}
type AllocatedCpuResources struct {
CpuShares int64
}
type AllocatedMemoryResources struct {
MemoryMB int64
MemoryMaxMB int64
}
type AllocatedDeviceResource struct {
Vendor string
Type string
Name string
DeviceIDs []string
}
// AllocIndexSort reverse sorts allocs by CreateIndex.
type AllocIndexSort []*AllocationListStub
func (a AllocIndexSort) Len() int {
return len(a)
}
func (a AllocIndexSort) Less(i, j int) bool {
return a[i].CreateIndex > a[j].CreateIndex
}
func (a AllocIndexSort) Swap(i, j int) {
a[i], a[j] = a[j], a[i]
}
func (a Allocation) GetTaskGroup() *TaskGroup {
for _, tg := range a.Job.TaskGroups {
if *tg.Name == a.TaskGroup {
return tg
}
}
return nil
}
// RescheduleInfo is used to calculate remaining reschedule attempts
// according to the given time and the task groups reschedule policy
func (a Allocation) RescheduleInfo(t time.Time) (int, int) {
tg := a.GetTaskGroup()
if tg == nil || tg.ReschedulePolicy == nil {
return 0, 0
}
reschedulePolicy := tg.ReschedulePolicy
availableAttempts := *reschedulePolicy.Attempts
interval := *reschedulePolicy.Interval
attempted := 0
// Loop over reschedule tracker to find attempts within the restart policy's interval
if a.RescheduleTracker != nil && availableAttempts > 0 && interval > 0 {
for j := len(a.RescheduleTracker.Events) - 1; j >= 0; j-- {
lastAttempt := a.RescheduleTracker.Events[j].RescheduleTime
timeDiff := t.UTC().UnixNano() - lastAttempt
if timeDiff < interval.Nanoseconds() {
attempted += 1
}
}
}
return attempted, availableAttempts
}
type AllocationRestartRequest struct {
TaskName string
}
type AllocSignalRequest struct {
Task string
Signal string
}
// GenericResponse is used to respond to a request where no
// specific response information is needed.
type GenericResponse struct {
WriteMeta
}
// RescheduleTracker encapsulates previous reschedule events
type RescheduleTracker struct {
Events []*RescheduleEvent
}
// RescheduleEvent is used to keep track of previous attempts at rescheduling an allocation
type RescheduleEvent struct {
// RescheduleTime is the timestamp of a reschedule attempt
RescheduleTime int64
// PrevAllocID is the ID of the previous allocation being restarted
PrevAllocID string
// PrevNodeID is the node ID of the previous allocation
PrevNodeID string
}
// DesiredTransition is used to mark an allocation as having a desired state
// transition. This information can be used by the scheduler to make the
// correct decision.
type DesiredTransition struct {
// Migrate is used to indicate that this allocation should be stopped and
// migrated to another node.
Migrate *bool
// Reschedule is used to indicate that this allocation is eligible to be
// rescheduled.
Reschedule *bool
}
// ShouldMigrate returns whether the transition object dictates a migration.
func (d DesiredTransition) ShouldMigrate() bool {
return d.Migrate != nil && *d.Migrate
}
// ExecStreamingIOOperation represents a stream write operation: either appending data or close (exclusively)
type ExecStreamingIOOperation struct {
Data []byte `json:"data,omitempty"`
Close bool `json:"close,omitempty"`
}
// TerminalSize represents the size of the terminal
type TerminalSize struct {
Height int `json:"height,omitempty"`
Width int `json:"width,omitempty"`
}
var execStreamingInputHeartbeat = ExecStreamingInput{}
// ExecStreamingInput represents user input to be sent to nomad exec handler.
//
// At most one field should be set.
type ExecStreamingInput struct {
Stdin *ExecStreamingIOOperation `json:"stdin,omitempty"`
TTYSize *TerminalSize `json:"tty_size,omitempty"`
}
// ExecStreamingExitResults captures the exit code of just completed nomad exec command
type ExecStreamingExitResult struct {
ExitCode int `json:"exit_code"`
}
// ExecStreamingInput represents an output streaming entity, e.g. stdout/stderr update or termination
//
// At most one of these fields should be set: `Stdout`, `Stderr`, or `Result`.
// If `Exited` is true, then `Result` is non-nil, and other fields are nil.
type ExecStreamingOutput struct {
Stdout *ExecStreamingIOOperation `json:"stdout,omitempty"`
Stderr *ExecStreamingIOOperation `json:"stderr,omitempty"`
Exited bool `json:"exited,omitempty"`
Result *ExecStreamingExitResult `json:"result,omitempty"`
}